Case Study: Anticoagulation

Question 1

What are the main uses of blood thinners?

Answer 1

Prevent thrombus formation in the venous circulation

Question 2

What is prothrombin time used for?

Answer 2

DOACs
= blood test for thinning

Question 3

What is INR used for?

Answer 3

Warfarin

Question 4

What are the anticoagulants in the UK?

Answer 4

Warfarin
Apixaban
Rivaroxaban
Edoxaban
dabigatran

Question 5

What do vitamin K antagonists do?

Answer 5

Inhibit the vitamin K dependent clotting factors

Question 6

What are the vitamin K dependent clotting factors?

Answer 6

II
VII
IX
X

Question 7

What is an example of a vitamin K antagonist?

Answer 7

Warfarin

Question 8

What are the DOACs?

Answer 8

Apixaban
Edoxaban
Rivaroxaban
Dabigatran

Question 9

What does Apixaban, Edoxaban + Rivaroxaban do?

Answer 9

Direct + reversible inhibitors of factor Xa

Question 10

What does dabigatran do?

Answer 10

Reversible inhibitor of free thrombin

Question 11

What are the risk factors of indication for DOACs?

Answer 11

Age >75 years
Hypertension
Diabetes
Symptomatic HF

Question 12

What are the contraindications for DOACs?

Answer 12

Active bleeding
Acute stroke
GI bleeding
Intracranial bleeding
Family history

Question 13

Which anticoagulant is there NOT a reversible agent for?

Answer 13

Edoxaban

Question 14

What are the different monitoring requirements for Warfarin?

Answer 14

INR
TTR
Reassess suitability

Question 15

Describe INR

Answer 15

Target range for indication

Question 16

How often are INR done?

Answer 16

When newly on it
= every week

Question 17

What is TTR?

Answer 17

Total time in range

Question 18

What is the INR range for most things?

Answer 18

2.0-3.0

Question 19

What is the target INR for most things?

Answer 19

2.5

Question 20

What are the exceptions to the normal INR range?

Answer 20

Mechanical valves in mitral position
Anti-phospholipid Ab syndrome
= 2.5-3.5

Question 21

What do anticoagulation patients have to carry?

Answer 21

Yellow book
= shows drug, dose, monitoring

Question 22

What is INR NOT used for?

Answer 22

DOACs

Question 23

What monitoring for DOACs are required pre-treatment?

Answer 23

Baseline clotting screen
U&Es
LFTs
FBCs

Question 24

Why does kidney function need to be assessed before DOAC use?

Answer 24

Drugs renally excreted

Question 25

What assesses the risk of clotting?

Answer 25

CHA2DS2-VASc score

Question 26

What assesses the risk of bleeding?

Answer 26

ORBIT score

Question 27

What is the anticoagulation male score for CHA2DS2-VASc?

Answer 27

1 or more

Question 28

What is the anticoagulation female score for CHA2DS2-VASc?

Answer 28

2 or more

Question 29

What is in the CHA2DS2-VASc?

Answer 29

CHF = 1 Hypertension = 1 Age >75 = 2 Diabetes = 1 Stroke = 2 Vascular Disease = 1 Age 65-74 = 1 Sex (female) = 1

Question 30

What is the low risk ORBIT score?

Answer 30

0-2

Question 31

What is the medium risk ORBIT score?

Answer 31

3

Question 32

What is the high risk ORBIT score?

Answer 32

4-7

Question 33

What is in the ORBIT score?

Answer 33

Older age >74 = 1 Reduced haemoglobin = 2 Bleeding history = 2 Insufficient kidney function = 1 Treatment with antiplatelets = 1

Question 34

What are the advantages of DOACs?

Answer 34

Lower intracranial haemorrhage + stroke risk Reduced monitoring Fewer drug + food interactions Less variable dosing

Question 35

What are the disadvantages of DOACs?

Answer 35

Higher cost NO reversible agent for Edoxaban Increased risk of GI bleed Caution with renal impairment

Question 36

What are the advantages of Warfarin?

Answer 36

Lower cost Easily reversed Reputable history

Question 37

What are the disadvantages of Warfarin?

Answer 37

Frequent monitoring Drug + food interactions Variable dosing

Question 38

When do you NOT offer anticoagulation?

Answer 38

When patient aged under 65 with AF + NO risk factors other than their sex

Question 39

When does Warfarin need to be taken?

Answer 39

At night

Question 40

When does rivaroxaban need to be taken?

Answer 40

With food

Question 41

What do you counsel the patient about with Warfarin?

Answer 41

Don't massively change your diet = can affect INR score

Question 42

What should you never do if you miss a dose?

Answer 42

Double up on a dose

Question 43

What are some signs of bleeding?

Answer 43

Blood in urine or stool Blood in sputum Blood in emesis Bleeding that not resolved or slowing within 10 mins

Question 44

What are some signs of clotting?

Answer 44

Chest or unilateral leg pain SOB Elevated HR (>100bpm) Unilateral lower extremity swelling